1. Field of the Invention
This invention relates to a processing apparatus and a processing method, and more particularly to a processing apparatus and a processing method suitable to removing photoresist used in lithography.
2. Background Art
In a lithography step of a process of manufacturing a semiconductor device or a liquid crystal panel, for example, an organic resist film is typically used as a patterning mask. The resist film needs removing after the patterning is completed. Methods for removing a resist film include a method of heating and dissolving the resist film with an organic solvent or the like. However, use of an organic solvent involves additional costs in facilities for waste liquid disposal. In particular, recent upsizing of semiconductor wafers and liquid crystal panels increases the amount of waste liquid generated in the process of resist peeling. This causes a problem of the associated increase in disposal costs and environmental loads.
JP 2001-250773A, for example, discloses a technology of spraying water vapor of 70 to 200° C. onto a substrate to peel and remove a resist film.
However, in particular, low molecular weight ingredients in the organic resist are left dissolved in water at high temperatures. Therefore, even if waste liquid is passed through a filter to recover and reuse water from the waste liquid, the resist is not trapped by the filter and is passed through the filter together with water. As a result, unfortunately, the water contaminated with resist is used again as vapor for resist peeling.